Lesson 1: The Molecular Machinery
Duration of Days: 4
Lesson Objective
Students will be able to explain the electrochemical and mechanical steps of the Sliding Filament Theory to describe how muscles contract at the molecular level.
How do invisible protein interactions create physical force? What happens at the "handshake" between a nerve and a muscle?
Sarcomere, Actin, Myosin, Tropomyosin, Calcium Ions (Ca2+}, Acetylcholine (ACh), Neuromuscular Junction (NMJ).
HS-LS1-1: Structure and Function (Protein synthesis/collagen/muscle proteins).
HS-LS1-2: Hierarchical Organization of Multicellular Organisms.
Analyzing cause-and-effect sequences in technical passages; identifying the "main idea" of a biological process description.
Description: A deep dive into the microscopic anatomy of a muscle fiber.
Purpose: To establish the cellular foundation of movement.
DOK Level 2.
The science of Botox: How a toxin blocks the NMJ to paralyze muscles; the role of electrolytes (Calcium/Magnesium) in preventing cramps.
Students often think muscle fibers "shrink" or "disappear" during contraction rather than sliding past one another.
Use physical "sarcomere kits" (pipe cleaners/beads) for tactile learners; provide a "sequencing card" activity for students to order the steps of contraction
Student-created stop-motion animation or a labeled diagram showing the 4 stages of the cross-bridge cycle.
Marieb’s Human Anatomy & Physiology or OpenStax (Free/Digital) A&P Ch. 10.2; Sliding Filament Model kits; interactive "Bio-Digital" software.